Introduction to Laozi: Laozi, also known as Lao Dan, whose original name was Li Er and whose courtesy name was Boyang, was a great philosopher and thinker in ancient my country and the founder of the Taoist school. He was regarded as the ancestor of the Li surname by the emperor of the Tang Dynasty. His book "Tao Te Ching" is still a masterpiece and has a profound influence on the development of Chinese philosophy.